Under the proposed legislation, GPs would have greater control over treatment but critics are opposed to the move over fears that private companies would have a greater role in the NHS.

Mr Burnham told MPs: "People outside will struggle to understand how Members of this House could make such momentous decisions without having carefully considered all of the facts and all of the evidence."

The bill had threatened to split the Coalition Government with Health Secretary Andrew Lansley coming under repeated criticism for falling to communicate the reforms with doctors and the public.

He said: "They do not represent a balanced view, they are not a prediction of the future. They set out a worst-case scenario to challenge decision making.

"The point is that we have looked at that balanced view of capturing where the risks and indeed the benefits indeed lie in the impact assessment.

"But publication of the risk register would prejudice the frankness and integrity of the decision-making processes of government and the Government is opposed to their publication."

Mr Burnham pledged to continue the campaign against the bill and said: "We have given this fight everything that we had. All I can say is our fight will go on to protect and restore this party's finest achievement."